Products in a retail store may be arranged at respective product positions along fixtures such as shelves, racks or other displays. The product positions may for example be selected to maximize sales by promoting certain products and/or to improve logistics of the store. Product positions for at least some products may be changed quite often and it may be difficult to maintain an updated record of the actual product positions.
Knowledge of the actual product positions may for example save time when products are restocked as persons bringing new items of the products to the fixtures of the store (e.g. from a storage room, a warehouse, or a supply truck) need not search through the fixtures of the store for the correct product positions at which to arrange the new items of the respective products.
The position of an object may generally be determined or estimated using signals transmitted between the object and a number of reference points. Received signal strengths for such signals indicate the distances traveled by the signals, which may be employed to estimate the distances between the object and the reference points. Using methods such as trilateration, the position of the object may then be estimated based on these distances.
A retail store may contain many obstacles (such as fixtures and products) which may obstruct signals or which may cause signals to be reflected (or attenuated) before reaching a sensor recording the received signal strength. The above described positioning methods may therefore be relatively inaccurate when applied in a retail store. Hence, new methods and systems for estimating positions are desirable.